Field of the Invention
The present invention relates to a bonding method for a flexible substrate, and more particularly, to a method of bonding a flexible substrate to a carrier substrate in order to facilitate handling of the flexible substrate.
Description of Related Art
In response to the advent of the information society, there is increasing demand for high-performance displays for displaying various forms of information, such as images or graphic characters, in order to rapidly transfer various types of information. According to such demand, the display industry has shown rapid recent growth.
In particular, interest in flat panel displays (FPDs), such as liquid crystal displays (LCDs), plasma display panels (PDPs) and organic light-emitting displays (OLEDs), is rapidly increasing, since such displays have a large size and a thin profile and are relatively lightweight.
Due to the continuously increasing demand for thin lightweight FPDs, flexible substrates having a thickness of 2 mm or less have recently been developed and have been employed in the industry.
However, it is somewhat difficult to transport or process such a thin substrate alone, since the thin substrate may be damaged or sag during transportation or processing thereof, due to the thinness thereof. The thin substrate is transported and deposited after being bonded to a carrier substrate supporting the thin substrate. The carrier substrate is separated from the thin substrate after the completion of the transportation and deposition processes for the thin substrate.
FIG. 1 is a conceptual view illustrating the process of fabricating an LCD module using a thin substrate bonded to a carrier substrate. As illustrated in FIG. 1, the LCD module may be fabricated by forming a color filter (CF) and a thin-film transistor (TFT) array on a thin substrate bonded to a carrier substrate and subsequently separating the carrier substrate from the thin substrate.
In order to fabricate a high-quality display module using the thin substrate bonded to the carrier substrate, high bonding quality between the carrier substrate and the thin substrate is required. That is, it is necessary that no trapped air or particles be present in the bonding surface of either the carrier substrate or the thin substrate.